How do I fix DC Bus Undervoltage (Alarm 1023) on a Solis?

Check whether the input voltage is too low for the inverter to run. Then: Restart the inverter.

Solis

UN-BUS

DC Bus Undervoltage (Alarm 1023)

DC bus voltage too low. Variants UN-BUS01 and UN-BUS02 (abnormal display).

Common causes

PV input voltage too lowInternal fault

What to check

STEP 1

Check whether the input voltage is too low for the inverter to run.

STEP 2

Restart the inverter.

Escalate if

Input healthy but alarm persists

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